Sand-blast apparatus.



J. D. MURRAY. SAND BLAST APPARATUS. AHLIOATION FILED JUNE 3, 1908.

Patented July 18,1911.

4 SHEETS-SHEET 1.

J. D. MURRAY.

SAND BLAST APPARATUS.

APPLIGATION FILED JUNE s, 1908.

998 1 1 1 c Patented July 18, 1911.

4 SHEETS-"SHEET 2.

J. 1), MURRAY. SAND BLAST APPARATUS.

1L 11L 9 11 00 11 m J m t H m a P am 0 9 1 3 E N U J E L I .P. N 0 I T AG I L P P A 4 $HEETSSHEET 3.

ra a

JANE/V727 WITNESSES J. D. MURRAY.

SAND BLAST APPARATUS.

AIPLIOATIOK FILED JUNE a, 1908.

Patented July 18, 1911.

4 SHEETSSHEET 4.

1B VETVTOR JOHN D. MURRAY, SAN FRANCISCO, CALIFQRNIA.

SAND-BLAST APPARATUS.

Specification of-Letters Patent.

Patented July 18, 1911.

Application filed June 3, 1908. Serial No. 436,407.

To all whom it may concern:

Be it known that I, JoHNl). MURRAY, a citizen of the United States, anda resident of the city and county of San Francisco and State ofCalifornia, have invented new and useful Improvements in Sand- BlastApparatus, of which the following is a specification.

This invention relates to improvements made in apparatus or appliancesfor scouring, cleaning, cutting, abrading or finishing surfaces of woodor metal by what is technically termed the sand blast.

The invention has for its object to pro- 'vide a sand-blast apparatusoflarge capacity for doing work on a large scale and under conditionswhere the surfaces to be operated on, or the work to be done,-may

besituated above the apparatus at a. con

siderable distance from the ground, or from the place where thesupply-tank and the aircompressing plant are stationed. I

A further object of the invention is to provide means for moving thesand or other solid material through a conducting-pipe for aconsiderable distance horizontally, or

. for raising it through a perpendicular conductor by pneumatic pressureapplied under such conditions that any liability of clogging or chokingthe material will be overcome and the material will flow to thesandblast nozzles under uniform pressure when the jets are working atconsiderable distance from the supply.

A further object of the invention is to provide means for producingcontinuous progression or travel of the abrading substance or materialthrough a closed conductor under varyin conditions in the bull: orquantity of solidmaterial carried by the air, and for conveying the sameeitherhorizontally or perpendicularly, for a considerable distancewithout liability of checking or obstructing the passages.

The invention has for its object also tiimprove the delivery nozzle ofthe apparatus in several points, particularly with the view to secure aregular discharge of the material in a stream of uniform character; alsoto afford facility for repairing or renewing the parts of the nozzlethat are subjectto wear.

To these ends my said invention comprises certain novel parts andcombination of parts producing an improved machine or apparatus foroperating with the sand-blast, all

as hereinafter described at length and point-- ed out in theclaims atthe end of this specification.

. Figure 1 of the drawings represents in elevation the complete machineor apparatus of my invention for doing work with the sand-blast. Fig. 2'is a transverse sectionalview on an enlarged scale of the couplingchamber on the supply tank to which the conducting-pipe or hose iscoupled; the same showing the coupling-chamber in side-elevation and theupper portion of the tank 1n transverse section. Fig. 3 is a plan ortop-view of the supply-tank and the coupling-chamber, the latter beingshown in horizontal section. Fig. 4 is a side-elevation of Fig. 3, withthe side of the tank partly broken away to expose the parts inside. Fig.5 is a side-view on an enlarged scale of one of the accelerating nozzlesin the length of the hose between the source of supply for the sand andthe sand-blast nozzle. Fig. 6 is a longitudinal sectional view of Fig.5. Fig. 7 is a longitudinal sectional-view of the last one of theaccelerating devices in the line of the hose to which the sand blastnozzle is coupled. Fig.

larged scale of the sand-blast nozzle through which the abradingmaterial is applied and directed against the surface to be treated. Fig.9 is a side-view of the removable tip of the nozzle shown in Fig. 8.Fig. 10 is an end-view of'the tip. Fig. 11 is a side-view of the splitsleeve or part that confines the removable tip in place, and Fig. 12 isan, end-view of the sleeve. Figs. 13 and 15 show two forms of detachabletip for the nozzle, and Figs. 14 and 16 are end views respectively ofthe parts represented in Figs. 13 and 15. Fig. 17 illustrates amodification of my invention designed to-provide a sand-blast apparatusof a more portable character than the complete apparatus shown in Fig.1.

It is obvious that in the application of sand blast to the variouscircumstances of use, such as cleaning the hulls and other parts ofmarine vessels, the walls of build-- ings and various kinds ofconstructive material employed in the arts, to remove paint oXid scale,dirt or discoloration, that the apparatus employed has to be greatlymodified in extent and detail.

herewith and forming a part ofthis specification consists in so far as Iam able to 8 is a longitudinal sectional view on an en- The apparatusshown in the drawings illustrate it, a normal arrangement of sand blastapparatus, and is an evolution or elaboration ot such apparatus as isdescribed in my previous l ietters l atent, namely: licttors latent No.'TT3,6G5, dated November 1st, llltl-l; No. W331i), dated February 21st,1905 and No. 818,776, dated April 21th, 1906, all in sand blastapparatus.

The sand employed is sometimes of tWo grades of fineness, which forreasons not very well understood produces a better and more rapidetlect, supposedly because the larger grains fracture and the finer onesremore obduratc scale. The horizontal position of the tanl; or receivera causes a nearly equal gravity pressure in the several compartments;the mobility of the dry sand causing it to act as a liuid and inproportion to the head.

In the complete apparatus of my invention the supply-tank a. is ofsutiicient ca pacity to supply several sand-blast nozzles, and provisionis made for varying the number of nozzles and for regulating the sup plyor feed of the material, according to the number of nozzles in'use atone time. For this purpose the last section. 0 in the line of hose l) isprovided with couplingsockets c at intervals along the pipe to each ofwhich connection or a sand-blast nozzle 7 can be made. This last sectionbeing formed of a rigid pipe it can be suspended from points oi supportalong the line 01" work by means of slings t, as illustrated in Fig. 1,or by other supporting means that will permit the pipe to be shifted ormoved from point to point as the Work is carried forivard.

. An important feature in sand-blast apparatus of my invention consistsin introducing at diltcrent points in the passages and conductorstraversed by the stream of abrading material, a jetof compressed air, asa means both of augmenting the working pressure at those points where itmay be necessary or movement, or increase the pneumatic pressure in theconductor; also at other points in the line of travel where there isliability of the material chokii'ig or obstructing the conductor; as,for example, at or in the vicinity of the outletspoutthrough which thematerial passes from the supply-tank into the line of hose, theconducting passages leading from the tanlr to the hose. and in theoutlet-passage from the coupling chamber. These accelerating jets as lhave termed them, are either supplied trom a separate source, ordirectly from. the compressor that turnishes the air from thesupplytanlr. Usually the nozzles g are supplied from an equalizing tanlrm connected with the air-compressor "hrough a line of pipe or hose 71;the tanlr m being itself connected with the air-compressor by a hose p,

desirable to accelerate the' eoaiizi.

In the nozzles 9 shown in the details Figs. 5 and tithe air in thechamber 2 will be under substantially the same pressure as that in thestorage-tank m, and being forced through the annular space between thenoz- 21s 3 and the surrounding walls of the chamber 2 it will impingeagainst the sandcharged stream issuing from the end, of the nozzle andthereby increase the force or pressure above that Which comes from thesupply-tank.

' The nozzle is fixed in the chamber 2 by a threaded joint 4, and ascrew-coupling 5 connects one end of the tube 3 with the conducting-hoseZ) on one side, but at the other end the chamber and the conductor areconnected together by a threaded sleeve 0. This construction permits thenozzle Sand its casing or chamber to be readily removed for renewing orcleaning the parts. It also permits the number of accelerating nozzlesto be increased or reduced, according" to the requirements of the work,by employing sections of pipes, or conductors, of different lengths. lnthose situations where the material has to be elevated perpendicularlyto a greater height as the Work goes on, or under other conditions Whereit is necessary to increase the pressure in the conducting hose atdifferent points in its length, the number of nozzles Q can be varied tosuit the needs of the Work. To. the complete apparatus of my inventionsimilar nozzles are placed in the conducting-passages at the outlets inthe bottom of the tank to prevent the passages from becoming; checked orobstructed, and with that objectto insure a continu ous movement of thematerlalthroug'h the conductors, and an effective pressure at the pointof delivery regardless of the length of the line of hose.

The interior space of the tank a is di vided by a partition 7 intoseparate compartments uv, each having an opening in the top closed by aremovable hand-pole plate 9 for introducing the sand, and an, outlet inthe bottom through which the material passes into and is conveyed by aconducting; pipe or'passage to the coupling-chamber s on the top of thetank. The last-named chamber is connected with the compartment u by apipe 15 carried from the outlet 8 through the body of the tank upwardand out through the top. and with the compartment '1. by the pipe 16leading from the outlet 10. Valves 12-13 are )rovided for shutting otteither compartment from the cou pling-chamber so as to take theabrading' material from one compartment: while the other is beingcharged. This combination of a common coupling-chamber with the twocompartments, and the means provided for connecting and disconnectingthe comtments one separately oi the other, en-

es the apparatus to be kept in operation seam;

without shutting ofi' the sand-blast nozzles when the supply-tank is tobe recharged; for the pressure can be shut off from one compartment asoften as it becomes neces sary to open and recharge it with material,without interrupting the supply to the nozzles from the othercompartment. This arrangement has the advantage, further, of permittingthe use of two different grades or kinds of abradingmaterial eitheralone or together on the same work; to which end.

the compartment u can be charged with a difierent material from thatcontained in compartment 2:, and the coupling-chamber then be suppliedfirst with material from one compartment, and afterward from the othercompartment, by opening or closing the valves in the required order. Twokinds of material may be used together, also, by taking the supplysimultaneously from both compartments, and by this means it is possibleto vary the character or quality of the jets delivered at the sand-blastnozzles according to the needs of the work.

A. nozzle 20 in the tube or passage that connects the outlet-spout ofthe compartment at with the coupling-chamber s on the top of the tank,and another nozzle of the same characterin the corresponding passage 16that intersects and extends across the spout-18 under the othercompartment 0'' of the tank, are arranged to deliver jets of air in thesame direction in which'the material is moving, and thereby raise thepressure at those points where it may be required,

For supplying air to the nozzles at the outlets 8-l0, a pipe 23 iscarried from the pipe to on the top of the tank downward through thecenter of each compartment to the nozzle-casing under the outlet, wherethe pipe 23 and the nozzle-casing 15 join together in a chamber 26 thatis somewhat larger than the butt end of the nozzle which itincloses, andis provided with a screw-threaded socket 27 for the nozzle. The latterhas a screw-thread fitted to the socket to form a tight joint therewithwhen screwed in place, and in the portion inclosed by the chamber ithasperforations 28 through which the air passes into the nozzle. An ejectory in the coupling-chamher is similarly arranged, but instead of takingthe air from the same source as the nozzles in the outlets under thetank, I prefer to connect the nozzle y directly with the tank m andemploy the pressure in that tank to increase the force of the outgoingstream of material whereit passes into the conducting hose 1).

The coupling-chamber s and its ejectornozzle are constructed with theview to facilitate repairs to the parts, and the renewal of those partswhich are exposed to the greatest cutting action or wear of thematerial. This is the case particularly with the throat of theoutlet-passage in the neck of the coupling-chamber, and with the tip ofthe ejector. Both the tip of the ejector, and the lining 29 of theoutlet are made de- 70 tachable.

The stem y of the ejector-nozzle 3 extends through a stuffing-box 30 inthe back wall of the chamber, and its butt end outside the chamber issurrounded by a tubular casing 31 having a screw-cap 32 in the end inwhich is a threaded socket for the end of the tube 3/. The latterextending through the cap is provided with a hand-wheel 33 for adjustingthe nozzle in the throat of the chamber. V

For the purpose of replacing the wearing surface of the outlet, thecontracted neck 8* of the chamber is a separate piece attached to thebody by a screw-joint, and its inner surface or lining is a loose sleeve29 removably fitted to the throat of the chamber, so as to be removedwhen worn and a new linin substituted for it.

Airis supplie to the casing 31 from the tank m through a hose 34 whichis coupled to the connection provided for that purpose on the stationaryair-pipe w on the supply-tank. Through these connections and conductorsall the compartments and the nozzles also receive air from the tank mthepressure being regulated in the compartments u.'v by means of the valves57-58 on the pipe w, and in the several nozzle-casings or chambers bythe valves 596Q in the pipes 2325. -lVhere the nozzle-blast f is beingused ataconsiderable distance from the tank a and the compressedair-tank, a steady and even jet may be insured by connecting 'the endsof the conductors ZJ--Ch with an equalizing tank or chamber.

The sancl-blast nozzle f is of novel construc ion in several features,that have for their object chiefly to increase the durability of theparts and passages in which the jet of abrading material is formedandthe tip or part through which it is discharged.

The construction of these parts will be understood more clearly byreferring to the details Figs. 8 to 16.

From the threaded socket 40 in the butt end of the nozzle to the frontend in which the tip 43 is fixed, the interior space is divided by atapered nipple 42 into a central passage 44; forming a contractedcontinuation of the connected tube or hose 41, and an annular space 45surrounding the nipple and extending beyond the end of that part in acontracted throator passage 47 of about the same dimensionsdiametrically as the tip 42. The part 48 is a loose sleeve removablyfitted to the chamber andforming a wearing surface or lining that can bere placed by a new one when worn. Being of tapered form and providedwith a screwthreaded end 49 extending beyond the end of the nozzle-body,it is drawn forward to a close seat in the surrounding chamber when thesleeve or couoling-member til is screwed on. kl. split socket 652 on theend of the part 61 is screw-threaded externally for a nut 63, by meansof which the detachable tip 43 is clamped in the socket on beinginserted at the "front end. Separate orifices of different forms, can beused from time to time as the character of the work may call for varyingforms of jet, by removing one style of tip and fixing another in placein the socket. Figs. 13 and 15 illustrate two different styles of tipsfor that purpose. The tapered nipple 42 in this nozzle is of novelcharacter in having several forwardly inclined slits 46 in its outerwalls, so arranged with relation to the walls or the surrounding annularspace a5 and of such size or width that relatively thin jets or streamsof air only will escape and be projected against the surrounding walls,without carrying through the slits particles of the abrading material. The etlect of these outwardly flowing forwardly inclined jets escapingthrough the slits above described, and thereby mountaining a constanttlow of air in a thin stream or tihn against and over the wallssurrounding the delivery-end oi the nipple, is to moiflity or soften thecontact of the stream of abrading-material at its point of deliverywhere it leaves the end of the nipple, and thus reduce the wear on thesurrounding walls of the passage. The form of this nipple i2 is shown inFigs. 9 and 10. These features of construction are adapted to in creasethe durability of the nozzle, and to improve effectiveness in operationin delivering a well defined jet without scatteringor wasting thematerial. .c in acceleratin jet is also interposed between the nozzlebody and the conductor from which it talres its supply, as a means ofincreasing and varying the pressure in the sand-blast nozzle over thatwhich is due to the pressure in the supplytanlr and the hose. Thisadditional pressure regulating means consists of the receive.ff-ClltlllllJEl connected with the air-pipe it by a coupling, andcontaining a valve or having a hollow stem 36 the butt end of whichextends through a tubular ca ing 1-59 on the end of the chamber The*asing is of larger diameter than the stem of the nozzle and isconnected with source ot pressure by means of the tube 37 in which is apressure-regulating valve 38. in the butt end of the valve-stem areperforations to admit the air or steam into the hollow s" Ill as. Thevalve has a conical head titted to a ot correspondi w orm h outet-passage, and from the end of t can; it

which the air or steam is delivered into the outlet.

The casing 39 is connected with theairpipe h by the tube 37 and thechamber 35 is connected with the conductor 6 by a short pipe 5 throughwhich the material enters the chamber. Provision is made for introducingair from the pipe h into the'chamber in addition to that which passesthrough the conductor, by connecting the chamber with the pipe itthrough a tube h This last mentioned tube is carried through theconnection 5 thereby reducing the numher of apertures and couplings inthe chamber. The pressure supplied through this connection is regulatedby a valve 39"..

The more simple form or construction oit sand-blast apparatusillustratedin Fig. 1? is of a more portable character than the apparatus of myinvention above described; being adapted for operating on a smallerscale and under conditions calling tor a rela tively light pressure anda jet carrying a line abrading substance. Tn this portable apparatus thecompartment is fed with the abradingmaterial through the open hopper 50,and the material is "forced into the conductor Z) by the air taken fromthe tank m acting through the nozzle 53 and the cones ot' the injectorin the chamber 51. The supply-tank a? is therefore not under pressure asare the compartments l/.'?J in the supply-tank a,but in other respectsthis more simple form of the apparatus is similar to the machinerepresented in Fig. l; the arrangement of accelerating nozzles in theline of conductors Z) h in and the coupling-chamber 85 to which thesand-blast nozzle f is connected being practically the same.

tilteani pressure may be substituted for air in the chambers of thenozzles 57 in the line of conducting hose. it can he used to advantagein place or air particularly in the last chamber 35, to which the nozzleis coupled, as the effectof introducing steam into the material at thatpoint in the corn ductor is to condense the line dust which otherwisebecomes a source oi? annoyance and discomfort to the workman.

1. in sand blast apparatus, a main tank or receiver containing abradingmaterial disposed in compartments, each compartment having acontrollable connection to discharge ways for sand and air at thebottom, a conducting pipe therefroai to the discharge nozzles and inconjunction therewith, a second or reintorci pipe of ztir under hi 'herressure and connections to the main pipe as rendered necessary by lengthor o struction the latter, substantially as speci- 2. ln sand blastapparatus, a main tanh receiver to contain air under pressure andabrading material, compartments therein and connections from thesecompartments to a main pipe leading to abrading 'discharge nozzles, apipe conducting air under pressure to the several compartments, aseparate air pipe under a higher pressure parallel to the first or mainpipe and controllable' connections between the two lines of pipes so thesupply of air can be increased as necessary or desired, substantially asdescribed. v

3. In sand blast apparatus, a portabl main tank or receiver withcompartments for sand and air under pressure, outlets at the bottom ofthese compartments. for air and sand and a main pipe connecting tonozzles, in combination with a fixed auxiliary tank or receivercontaining air under a superior pressure and connections from this'tothe-main conducting discharge pipe at points-where the greater airpressure is required, substantially as specified.

4. In sand blast-apparatus, a supply of sand or other abrading materialand air under pressure disposed in compartments of. a main tank orreceiver, pipes leading therefrom to nozzles to apply the .abradingmaterial, asecond tank or receiver connect- I ingto a second line ofpipes containing air undera higher pressure, and a controlling orreducing valve to regulate the pressure in this secondary receiver andpipe line and controllable connections between the two pipe lines bywhich the force of the air and sand can be regulatedat the nozzles,substantially as specified.

therefrom with controllable connections to the nozzle pipes at variouspoints by which the air pressure can be augmented as necessary andvalvesto control the volume and degree ofthe supplementary air pressure,1

substantially as specified. p

. JOHN D.MU RRAY.'

Witnesses: EDWARD E. OSBORN, M. REGNER.

